Bolt assembly comprising a pivoted firing pin serving also as the ejector and an extractor



3,142,923 RVING g- 1964 E. SJVARTANIAN ETAL BOLT ASSEMBLY COMPRISING A PIVOTED FIRING PIN SE ALSO AS THE EJECTOR AND AN EXTRACTOR s Sheets-Shet 1 Filed March 12, 1962 INVENTORSI EDWIN S. VARTANIAN BY QOSEPH A. BADALI ATTORNEY g- 4, 1954 E. s. VARTANIAN ETAL 3,142,923

BOLT ASSEMBLY COMPRISING A PIVOTED FIRING PIN SERVING ALSO AS THE EJECTOR AND AN EXTRACTOR I5 Sheets-Sheet 2 Filed March 12, 1962 INVENTORSI EDWIN S. VARTANIIAN JOSEPH A. BADALI ZMMWQW ATTORNEY g- 4, 1964 E. s. VARTANIAN ETAL 3,142,923

BOLT ASSEMBLY COMPRISING A PIVQTED FIRING PIN SERVING ALSO AS THE EJECTOR AND AN EXTRACTOR Filed March 12, 1962 3 Sheets-Sheet 5 0 v 55 in W mm W 1 M... r

Y INVENTORSI EDWIN S. VARTANIAN JOSEPH A. BADALI HG ,ZMM

ATTORNEY United States Patent "ice 3,142,923 BOLT ASSELY COMPRISWG A PIVQTED FIR- ING PIN SERVING ALSO AS TIE EJECTOR AND AN EXTRACTOR Edwin S. Vartanian, North Haven, and Joseph A. Badali, Branford, Conn, assignors to Olin Mathieson Chemical Corporation, a corporation of Virginia Filed Mar. 12, 1962, Ser. No. 178,972 7 Claims. (Cl. 42-25) This invention relates to a bolt assembly for firearms and to a method of fabricating and assembling the same. The bolt mechanism disclosed is suitable for use in automatic, semi-automatic, lever action or slide actuated firearms, and is thus adapted for use in a complete line of firearms having a maximum number of similar and interchangeable parts.

In firearms such as rifles or the like, it is necessary to provide a bolt to lock the breech while a cartridge is fired, a firing pin to fire the cartridge, an extractor to withdraw the cartridge from its firing position, and an ejector to eject the spent cartridge from the receiver. These functions are usually performed in the prior art by a number of separate elements which are mounted in the bolt and in the receiver in various ways. The present invention provides a bolt assembly which performs all these functions with a minimum number of moving elements all of which are carried by the bolt. The firing pin is a single integral element which also functions as an extractor and as an ejector. The only other moving element in the bolt is an extractor claw which cooperates with the firing pin as a twin extractor to withdraw the spent cartridge from its firing position. The novel bolt of this invention provides all the advantages of simplicity, dependability and economy in a single integral unit which performs all the functions of a bolt, firing pin, extractor, and ejector.

It is therefore an object of this invention to provide a novel bolt assembly for firearms which is suitable for use in automatic, semi-automatic, lever action and slide actuated firearms.

Another object of this invention is to provide a novel bolt assembly having a firing pin which is a single integral element functioning as a firing pin, extractor and ejector.

A further object of this invention is to providea novel method of forming and assembling a bolt assembly for firearms. 3

Another object of this invention is to provide a bolt assembly for firearms which has a minimum number of parts, is simple in design and which can be readily and economically produced. 1

Other objects and advantages of this invention will be- 3,142,923 Patented Aug. 4., 1964 mounted in a fixture wherein heat and pressure can be applied to the bolt sections to fuse the sections together mto an integral unit.

FIGURE 1 illustrates a bolt generally designated 1, slidably mounted in the receiver 2 of a firearm. A barrel 3 is secured to the front of receiver 2 by screw threads 4 or equivalent means. The bolt 1 is shown in FIG. 1 in its firing position in the receiver 2 with locking plate 5 engaged in a notch 6 in the receiver. The bolt 1 abuts a cartridge 7, which is shown in firing position in the barrel 3. A projection 8, on the side of the bolt 1 actuates the operating lever 9 of a feed mechanism not shown. The

bolt 1 and the locking plate 5 are actuated by a lever 10,

ward ejecting position. A hammer 15 is mounted in the come apparent from the following description and drawreceiver by means not shown and is positioned to impact the firing pin when the bolt mechanism is in the firing position shown in FIG. 1 and the hammer is released by means not shown.

It should be noted at this point that when bolt 1 is used in an automatic or semi-automatic firearm, the locking plate 5 may be either omitted or locked in a retracted position flush with the top face of the bolt 1 to add weight to the bolt. Another alternative is to make the upper surface of the bolt solid by omitting the recess provided for the locking plate. Operating lever 10 is also omitted along with its actuating mechanism, and a spring (not shown) is interposed in the receiver between the rear wall of the bolt and the rear wall 14 of the receiver.

The bolt 1 is most clearly shown in FIGS. 2-6 and will be described in detail with particular reference to FIGS. 2-6. The bolt 1 has a generally rectangular body portion 16 and a tapered nose portion 17 at the front end thereof. The rear end of the bolt 1 terminates in a generally flat rear face 18, which may be provided with a circular recess 19. The top face of the bolt is recessed at 20 to accommodate the locking plate 5. Side wall 21 of the bolt is provided with a recess 29A to accommodate arm 13 of locking plate 5. The bottom surface of the bolt indicated at 22 is provided with a slot throughout its length generally indicated at 23 to accommodate portions of the feed mechanism (not shown) and the upper portion of hammer 15 as the bolt is moved rearwardly to its ejecting position.

The bolt 1 is made up of two separate sintered metal sections including an upper section 24 and a lower section 25 which are assembled in a manner which will be described in detail below. The sections have mating faces joined along the line 26 (FIG. 3) and are recessed to accommodate a firing pin 27, an extractor claw 28, a

spring 29, and a pair of plungers 30 and 3 1 (FIG. 6).

FIGURE 4 is a front end View of the bolt mechanism I shown in FIGURE 2.

FIGURES is a rear end view of the bolt mechanism shown in FIGURE 2.

FIGURE 6 is a sectional view taken along the line Lower section 25 is shown in detail in FIG. 6 with the firing pin 27, extractor claw 28, spring 29 and plungers 30 and 31, shown positioned in the recessed portion 32. The recessed portion has an irregular shape to accommodate the various elements positioned therein as is apparent from an inspection of FIG. 6. Upper section 24 of bolt 1 is provided with a recess which is complimentary to the recess 32 shown in section 25 and for that reason is not illustrated.

Referring now to FIG. 6, it should be noted that the firing pin 27, extractor claw 28, spring 29, and plungers 30 and 31 are mounted in a recess generally designated 32. Firing pin 27 is a rigid elongated element, extending beyond the ends of the bolt and is provided with a plurality of offset portions or projections. The front part of the firing pin 27 is designated an extractor portion 33 which may be provided with a recess 34 adapted to engage and grip the rim of cartridge 7 when the bolt is in the firing position shown in FIG. 1. The extractor portion 33 of the firing pin 27 engages the outer periphery of a cartridge such as cartridge 7 shown in FIG. 1 and cooperates with extractor claw 28 to function as twin extractors in removing the cartridge from the barrel. The recess 34 in the extractor portion 33 may be provided to aid in gripping the rim of the cartridge but is not considered to be necessary for most firearms and may be omitted. Spaced inwardly of the extractor portion 33 is a first projection 35, which has a front face 36 and a rearwardly tapered cam surface 37.

Front face 36 is adapted to contact the end face 7A of a cartridge 7 such as shown in FIG. 1, to fire the cartridge when the firing pin 27 is impacted by the hammer 15. The cam surface 37 is adapted to ride on the bottom wall 38 of a slot in the tapered nose portion. The slot in the tapered nose portion is merely a continuation of recess 32 extending into the tapered nose portion. The rear end of the firing pin 27 has a face 39, adapted to engage the rear wall 14 of the receiver when the bolt is moved to its rearward ejecting position. The rear end of the firing passed from a source (not shown) through electrode 74, the bolt section 24, the projections 5155, section 25, through electrode 75 and back to the source. Sufficient current is passed through projections 51-55 to melt these projections by resistance heating. Pressure is then applied to the plates 70 and 71 by means not shown, to press the bolt sections 24 and 25 into mating contact as shown in FIG. 3.

The bolt 1 after having been fused into a single integral unit is then provided with a firing pin, extractor claw, plungers and a spring. This is done by first inserting extractor claw 28 into the recess 32 through the front of I the bolt. Plunger 31, spring 29 and plunger 30 are then pin is cut away to define a second face 40 projecting outp 7 wardly beyond the rear face of the bolt 1. This second face 40 is adapted to be engaged by hammer 15 to impart a slight forward movement to the firing pin 27 which is effective to bring face 36 of the firing pin into impacting engagement with the end face 7A of cartridge 7 to fire the cartridge. A second projection 41 on "the firing pin 27 is adapted to be engaged by plunger 30, which urges the firing pin rearwardly due to the action of spring 29. Plunger .30 has a rounded cap portion A which functions as a pivot about which the firing pin 27 rotates as the firing pin is moved forwardly by the engagement of surface 39 with rear wall 14 of the receiver. A third projection 42 on the firing pin 27 engages pin 43, mounted in the body of the bolt to limit the rearward movement of the firing pin 27.

Extractor claw 28 is mounted on pivot pin 44, which passes through the body sections. Extractor claw 28 is engaged by plunger 31 and is urged in a counterclockwise direction toward the firing pin by the action of spring 29 which acts on plunger 31. The extractor claw 28 is provided with a hook portion 45, which engages behind the rim of a cartridge such as cartridge 7 in FIG. 1 and cooperates with notch 34 on the firing pin to function as a twin extractor to remove the cartridge 7 from its firing position in the barrel shown in FIG. 1.

' The method of assembling the bolt will now be described in detail with particular reference to FIGS. 6 and 7.

As pointed out above, the bolt body is formed from two sintered metal sections designated upper section 24 and lower section 25. One of the sections is formed with a plurality of raised projections such as projections 50-55 shown in FIGS. 6 and 7. It is apparent that these projections may be formed on either section 24 or 25. Each of the projections 50-55 is surrounded by a recess indicated by reference numerals 56-61. The recess surrounding each projection provides a place for the excess metal of the projection to flow into when the projections are melted by resistance heating to fuse the sections 24 and 25 together as will be described.

The sections 24 and 25 are assembled with their mating surfaces spaced only by the projections 50-55 and placed in a fixture such as is illustrated in FIG. 7.

The fixture has a fixed lower plate 70 and a movable upper plate 71 which is movable by means not shown. The mating faces 72 and 73 of the plates 70 and 71 are provided with electrodes 74 and 75 which are in contact with the sections 24 and 25 of the bolt. A current is assembled and inserted into recess 32 through the opposite end. Firing pin 27 is then inserted into the recess 32 through the rear of the bolt a sufiicient distance to allow projection 35 on the firing pin to clear the extractor claw. Extractor claw 28 is then pinned in place by pivot pin 44. Projection 41 on the firing pin engages plunger 30 and compresses the spring 29 as the firing pin is fully inserted. Pin 43 is then provided to engage projection 42 on firing pin 27 and locks the entire assembly in place.

The operation of the novel bolt of the instant application is as follows:

FIG. 1 shows bolt 1 locked in firing position with locking plate 5 engaged in recess 6 of receiver 2. Extractor claw 28 is engaged with the rim of cartridge 7 on one side of the cartridge and extractor portion 33 of firing pin 27 engages cartridge 7 in diametrically opposed relation to extractor claw 28.

In the firing position shown in FIG. 1 face 36 of projection 35 on firing pin 27 is slightly spaced from end face 7A of cartridge 7. Hammer 15 is held in cocked position by releasable means not shown. When hammer 15 is released, it impacts face 40 of firing pin 27 and drives the firing pin forward relative to the bolt body bringing face 36 of firing pin 27 into impacting contact with face 7A of cartridge 7 and fires the cartridge. The bolt 1 is then moved rearwardly by lever 10 which is actuated by means not shown. Cam slot 11 in lever 10 initially moves the locking plate 5 into flush relationship with the upper surface of bolt 1. Lever 10 then moves bolt 1 rearwardly toward wall 14 of receiver 2 with cartridge 7 engaged between the extractor claw 28 and extractor portion 33 of the firing pin.

The rearward movement of bolt 1 brings surface 39 of the firing pin into contact with rear wall 14 of the receiver 2. With surface 39 contacting wall 14, continued rearward movement of bolt 1 causes firing pin 27 to be moved forwardly relative to bolt 1 against the action of spring 29. As the firing pin moves forwardly relative to bolt 1, spring 29 is compressed and firing pin 27 rotates about rounded portion 30A of plunger 30. R0- tation of the firing pin occurs about portion 30A because the force applied to face 39 of the firing pin is axially ofi'set relative to the force being applied to the firing pin by spring 29. Cam surface 37 rides on surface 38 of the nose portion 17 and allows the front of the firing pin to move inwardly toward the extractor claw 28. Spring 29 is compressed during the forward movement of the firing pin and acts with increased force on extractor claw 28, thus increasing the grip of the extractor claw on the cartridge as it goes through the ejection cycle. I The inward movement of the front of the firing pin as the pin is being moved forward by the contact of face 39 with wall 14 is effective to pivot the spent cartridge about the hook portion 45 of the extractor claw and to eject the cartridge through an appropriate opening in the receiver. I

From the above description, it is apparent that the firing pin 27 performs the three separate functions of a firing pin, an extractor, and an ejector.

While the invention has been described in detail with respect to a specific embodiment, it is apparent that numerous minor changes in structure and operation can be made without departing from the spirit of the invention which is to be limited only by the scope of the appended claims.

We claim:

1. A bolt assembly for firearms comprising a body having two ends, a tapered nose portion at one end, a firing pin movably mounted in said body and protruding beyond the ends of the body, an extractor claw pivotally mounted in said body, a forward end of the firing pin having an extractor portion operative to engage the outer periphery of a cartridge, a projection on said firing pin positioned inwardly of the extractor portion and operative to contact an end face of said cartridge, said projection having a rearwardly extending cam surface operative to ride on said tapered nose portion to allow said firing pin to move toward said extractor claw as the firing pin moves forwardly relative to the body, a rear end of the firing pin having a surface operative to engage the rear wall of a receiver to impart a longitudinal forward movement to the firing pin, a recess in the rear end of the firing pin defining a shoulder operative to be engaged by a hammer to impart a slight forward movement to the firing pin to fire said cartridge, said extractor claw having a hook portion extending beyond said nose portion in diametrically opposed relation to the extractor portion of said firing pin, resilient means mounted in said body to bias the extractor claw toward the firing pin and to bias the firing pin rearwardly relative to said body, a projection formed integral with the rear end of said firing pin, said resilient means having one end engaging said projection to provide a pivot about which said firing pin rotates as the forward portion of the firing pin moves toward said extractor claw, stop means mounted in said body operative to engage the firing pin to limit the rearward longitudinal movement of said firing pin.

2. The bolt assembly of claim 1 in which the top of face of said body is provided with a recess to accommodate a locking plate, and a locking plate mounted in said recess for pivotal movement from a position flush with the top face of said body to a position where a portion of said locking plate projects above the top face of said body.

3. A bolt assembly for firearms comprising a body having a tapered nose portion on the front end thereof and a flat surface at the rear end thereof, an extractor claw pivotally mounted in said body and having a hook portion extending beyond the end of said tapered nose portion, a firing pin movably mounted in said body for linear and pivotal movement, said firing pin having a first end and a second end, said first end of the firing pin having a portion protruding beyond said tapered nose portion and operative'to engage the peripheral surface of a cartridge, a first projection on said first end having a front surface operative to engage the end wall of a cartridge to fire said cartridge, said first projection having a rear cam surface operative to engage said tapered nose portion of the body, said second end of said firing pin protruding beyond said rear end of said body and having a first surface and a second surface, said first surface operative to be contacted by impact means to impart a first forward movement to said firing pin to fire said cartridge, said second surface operative to contact an end wall of the receiver and impart a second forward movement to ,said firing pin to eject said cartridge, resilient means mounted in said body between said extractor claw and said firing pin to bias said extractor claw inwardly toward said firing pin and to bias the firing pin rearwardly relative to said body, stop means mounted in said body operative to contact a second projection on said firing pin to limit the rearward movement of said firing pin, said resilient means engaging said firing pin at a point axially spaced inwardly from said second surface to provide a pivot about which said firing pin rotates. l v

4. A breech bolt assembly for firearms having a receiver and impact means mounted in the receiver to strike a firing pin mounted in the breech bolt assembly to fire a cartridge, said breech bolt assembly comprising a generally rectangular body member having a tapered nose portion atone end and an end wall at the opposite end, said body member having an internal recess adapted to accommodate a firing pin, an extractor claw and a spring, an extractor claw pivotally mounted in said recess, a firing pin slidably mounted in said recess for longitudinal and pivotal movement, said firing pin comprising a rigid member extending longitidinally of the breech bolt assembly and having a first end extending beyond said nose portion and operative to engage the outer periphery of a cartridge positioned ad jacent the nose portion, a second end of said firing pin extending beyond said end wall of said body member, a plurality of projections formed integral. with said firing pin, a first projection positioned adjacent said first end of said firing pin and having a front surface operative to engage the end face of said cartridge for firing said cartridge when the firing pin is moved longitudinally, said first projection having a rearwardly extending cam face operative to ride on said tapered nose portion to cam said first end of said firing pin toward said extractor claw when the firing pin is moved longitudinally of said body member, a second projection formed integral with said firing pin adjacent said second end, spring means mounted in said body member adapted. to engage a front face of said second projection to urge the firing pin rearward relative to the body member and to provide a pivot about which said firing pin rotates when said first end of the firing pin is cammed toward said extractor claw, a rear face of said second projection terminating inwardly of said second end of the firing pin and adapted tobe engaged by said impact means to impart a first longitudinal movement to said firing pin to fire said cartridge, said second end of said firing pin terminating in a face adapted to engage the end wall of said receiver and impart a second longitudinal move ment to said firing pin, a third projection on said firing pin adapted to engage a stop means mounted in the body member to limit the rearward longitudinal movement of said firing pin.

5. The bolt assembly of claim 4 in which said body member is provided with a recess in the top surface thereof to accommodate a locking plate, a locking plate mounted in said recess and adapted to be pivoted upwardly from said recess into engagement with said receiver to lock the breech bolt assembly in the receiver and arm means formed integral with said locking plate extending downwardly in a recess in a side of said bolt assembly to connect said bolt assembly to an actuating means.

6. The bolt assembly of claim 4 in which said spring means is a coil spring provided with plungers at each end and having one plunger in engagement with said second projection and the other plunger in engagement with said extractor claw to pivot said extractor claw inwardly toward said first end of said firing pin.

7. A bolt assembly for firearms comprising a body, firing pin means slidably and pivotally mounted in said body to fire, extract and eject a cartridge, extractor claw means pivotally mounted in said body in diametrically opposed relation to said firing pin means, resilient means mounted in said body biasing said firing pin means rearwardly relative to said body and biasing said extractor claw means counterclockwise toward said firing pin means, a projection formed on a rearward portion of said firing pin means, one end of said resilient means engaging said projection to provide a pivot about which 7 v said firing pin can rotate, and stop means mounted in said body limiting the rearward movement of said firing pin means.

References Cited in the file of this patent UNITED STATES PATENTS 768,665 Johnson Aug. 30, 1904 

1. A BOLT ASSEMBLY FOR FIREARMS COMPRISING A BODY HAVING TWO ENDS, A TAPERED NOSE PORTION AT ONE END, A FIRING PIN MOVABLY MOUNTED IN SAID BODY AND PROTRUDING BEYOND THE ENDS OF THE BODY, AN EXTRACTOR CLAW PIVOTALLY MOUNTED IN SAID BODY, A FORWARD END OF THE FIRING PIN HAVING AN EXTRACTOR PORTION OPERATIVE TO ENGAGE THE OUTER PERIPHERY OF A CARTRIDGE, A PROJECTION ON SAID FIRING PIN POSITIONED INWARDLY OF THE EXTRACTOR PORTION AND OPERATIVE TO CONTACT AN END FACE OF SAID CARTRIDGE, SAID PROJECTION HAVING A REARWARDLY EXTENDING CAM SURFACE OPERATIVE TO RIDE ON SAID TAPERED NOSE PORTION TO ALLOW SAID FIRING PIN TO MOVE TOWARD SAID EXTRACTOR CLAW AS THE FIRING PIN MOVES FORWARDLY RELATIVE TO THE BODY, A REAR END OF THE FIRING PIN HAVING A SURFACE OPERATIVE TO ENGAGE THE REAR WALL OF A RECEIVER TO IMPART A LONGITUDINAL FORWARD MOVEMENT TO THE FIRING PIN, A RECESS IN THE REAR END OF THE FIRING PIN DEFINING A SHOULDER OPERATIVE TO BE ENGAGED BY A HAMMER TO IMPART A SLIGHT FORWARD MOVEMENT TO THE FIRING PIN TO FIRE SAID CARTRIDGE, SAID EXTRACTOR CLAW HAVING A HOOK PORTION EXTENDING BEYOND SAID NOSE PORTION IN DIAMETRICALLY OPPOSED RELATION TO THE EXTRACTOR PORTION OF SAID FIRING PIN, RESILIENT MEANS MOUNTED IN SAID BODY TO BIAS THE EXTRACTOR CLAW TOWARD THE FIRING PIN AND TO BIAS THE FIRING PIN REARWARDLY RELATIVE TO SAID BODY, A PROJECTION FORMED INTEGRAL WITH THE REAR END OF SAID FIRING PIN, SAID RESILIENT MEANS HAVING ONE END ENGAGING SAID PROJECTION TO PROVIDE A PIVOT ABOUT WHICH SAID FIRING PIN ROTATES AS THE FORWARD PORTION OF THE FIRING PIN MOVES TOWARD SAID EXTRACTOR CLAW, STOP MEANS MOUNTED IN SAID BODY OPERATIVE TO ENGAGE THE FIRING PIN TO LIMIT THE REARWARD LONGITUDINAL MOVEMENT OF SAID FIRING PIN. 